Apparatus for mixing liquids



July 28, 1964 1.. D. MINKLER 3,142,309

APPARATUS FOR MIXING LIQUIDS Filed Feb. 5. 1961 SYRJP RESERVOIR INVENTOR. L. D. MINKLER ATTORNEY United States Patent 3,142,309 APPARATUS FOR MIXING LIQUIDS Lee D. Minlder, 5309 Agnes St., Apt. 9, North Hollywood, Calif. Filed Feb. 3, 1961, Ser. No. 86,967 11 Claims. (Cl. 137-692) This invention relates to an apparatus for mixing a plurality of liquids.

Explanatory of the present invention, there are many situations wherein two or more liquids are to be mixed together in definite or specified proportions and a supply of the mixture is to be kept available for immediate use at all times. One such situation exists in the dispensing and sale of rootbeer wherein rootbeer syrup is supplied to the retailer in concentrated form. In preparing such syrup for use it is first mixed with water and the mixture kept in a storage tank or storage receptacle from which it is withdrawn periodically, carbonated, and dispensed. A typical proportion consists of one part rootbeer syrup to five parts water.

Heretofore, it has been customary to maintain the mixture in the storage tank or receptacle by refilling it from time to time with measured amounts of syrup and water, respectively. This involves making frequent observations as to the mixture remaining in the storage tank or receptacle and then measuring and emptying into it proportional amounts of syrup and water to maintain an adequate supply at all times. A primary object of the present invention is to provide an apparatus which will automatically supply to the storage tank or storage receptacle correct proportions of two liquids, such as for example rootbeer syrup and water, so as to maintain an adequate supply of the mixture in the storage tank or receptacle at all times.

More specifically, an object of the invention is to provide an apparatus for mixing liquids wherein measured amounts of each liquid will be released into the receptacle whenever the liquid level in the receptacle falls below a predetermined depth. To this end, an electrode is suspended in the storage receptacle and is normally immersed in the liquid therein. However, when the liquid level in the receptacle falls below the lower end of the electrode an electronic means is provided for supplying additional amounts of the liquids to the receptacle in the correct proportions. By the use of an electrode in the receptacle in lieu of float-actuated switches and the like, the ability to keep the storage receptacle clean is greatly facilitated. Also, the use of moving parts is eliminated.

A further object of the invention is to provide a liquid mixing apparatus having the above-mentioned characteristics wherein no high electric potential need be supplied to the electrode in the storage receptacle and consequently many dangers are eliminated.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

The figure is a wiring diagram of apparatus embodying the present invention.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, indicates a storage tank or storage receptacle in which it is desired to maintain a supply of mixed liquids "ice at all times and from which the mixture can be withdrawn at the time of use through an outlet 11. This receptacle is preferably formed of metal, such as for example stainless steel, and is electrically grounded as indicated at 12. It is supplied with liquid from at least two sources although the number may be increased if desired.

Where the two liquids are concentrated rootbeer syrup and water the concentrated rootbeer syrup may be maintained in a syrup reservoir 13 and supplied therefrom to the receptacle 10 through a positive displacement motordriven pump 14 in a connecting conduit 15. A gear pump is suitable for this purpose in that when the gear pump is driven for a predetermined length of time by its motor a definite or measured quantity of concentrated syrup will be transmitted from the syrup reservoir 13 to the receptacle 10.

' The water may be supplied from any suitable source, such as for example from a city water main, and when this is the case a pressure regulator 16 is preferably employed so that water will be supplied at constant pressure to a solenoid valve 17 in a conduit 18. With the water thus supplied to the solenoid valve at constant pressure, the opening of the valve for a predetermined length of time determines the amount of water supplied to the tank 10.

Within the storage receptacle 10 there is a working electrode A which is suspended in the receptacle. This electrode may be formed of stainless steel or the equivalent, and when'it is immersed in liquid in the receptacle it) it is electrically grounded to the walls of the receptacle through the liquid. However, when the liquid level falls below the bottom of the electrode A the connection to ground is broken. This electrode is electrically connected through a capacitor 19 to the grid 20 of a gas-filled triode, the anode 21 and cathode 22 of which are impressed with an electric potential derived from leads 23 that may be connected to a source of alternating current, such as for example conventional volt house current.

When the electrode A has its grounding connection with the wall of tank 10 broken by the falling of the liquid level in the tank below its lower end, the control grid 20 of the gas-filled triode permits current to flow between the anode 21 and cathode 22 energizing a relay 24 in circuit therewith closing contacts 25. These contacts are in circuit with a four-pole relay 26. The relay 26 has four contactors 27, 28, 29, and 30 which normally occupy the positions shown but which, when the relay 26 is energized, are thrown to the opposite positions.

When contactor 27 of relay 26 is thrown it serves to connect one of the leads 23 to the contactor 31 of a relay 32 and through this contactor to energize a motor starting relay 33 to close the circuit leading to the motor-driven pump 14. The shifting of contactor 28 as a result of the energizing of relay 26 connects the same lead 23 to one side of the solenoid valve 17 to cause the solenoid valve to open and permit water to flow through the conduit 18 into the tank 10. The contactor 29 performs no useful function as the result of being thrown when relay 26 is energized. In its normal position it serves to connect electrode A to grid 20 through capacitor 19. This connection is broken when relay 26 is energized. Contactor 30 performs no useful function in its normal position but when thrown as a result of energizing relay 26, it establishes a connection to ground indicated at 34.

When contactor 30 is connected to ground 34 the cathode circuit of a triode 35 is grounded as well as the oathode circuit of a triode 36. The triodes 35 and 36 may be separate tubes or may be in a single tube having two grids, two anodes and two cathodes and heated by a heating filament 37. The two triodes 35 and 36 are in resistance capacitance timing networks or circuits which control the length of time that the pump 14 operates and the valve 17 remains opened, respectively. These circuits are energized by the secondary of a step-up transformer 38 which also has a winding 39 that energizes the filament 37. When the resistance capacitor network containing the triode 35 has been energized for a predetermined length of time, current is permitted to flow through the relay 32 causing its contactor 31 to open and thus opening the circuit through relay 33 which shuts off the operation of the motor-driven pump 14.

In a similar manner, when the circuit including the triode 36 has been energized a predetermined length of time current is permitted to flow through relay 40 energizing this relay and shifting its contactors 41 and 42 from the position shown. The shifting of contactor 41 merely connects to ground indicated at 43, but the shifting of contactor 42 opens the circuit through the solenoid valve 17, thus allowing the solenoid valve to close after it has remained open a predetermined length of time.

The variable resistances 44 and 45 in the companion or parallel resistance-capacity timing networks are resistances of a dual potentiometer so wired that as this potentiometer is adjusted in one direction the timing of the network controlling the period of operation of the motordriven pump 14 is increased and the timing of the circuit controlling the solenoid valve 17 is decreased. Conversely, if the dual potentiometer is adjusted in the opposite direction the amount of syrup supplied per cycle of operation is reduced and the amount of water supplied is increased. In this manner, some adjustment of the exact ratio of syrup to water is permitted but once that the potentiometer has been given a definite setting or adjustment the ratio of syrup to water is constantly and electronically maintained.

When the relay 40 is energized its contactor 41 on connecting to ground 43, is the equivalent of electrically connecting the grid 20 of the gas-filled triode to ground. The grounding of the grid 20 prevents further current flow between anode 21 and cathode 22, thus opening the circuit through relay 24. The opening of relay 24 causes relay 26 likewise to open, restoring the contactors 27, 28, 29, and 30 to the positions shown. When relay 26 is deenergized, this of course releases relays 32 and 40. The winding of relay 40 is preferably shunted by a large capacity condenser 40:: in the neighborhood of from four to one hundred mfd. so that its opening is delayed slightly affording ample opportunity for contactor 25 to open before the grounding connection at 43 is broken.

45, 46, and 47 are three switches that are mechanically connected together so as to be swingable in unison through three positions. In the left-hand position which may be regarded as an off position, the entire system is disconnected. When these three contacts are in their central position a pilot light 48 will be energized, and when in the right-hand position a pilot light 49 will be energized. When the three contacts are in the central position a longer electrode B that is in the tank is electrically connected through the capacitor 19 to the grid 20. This electrode may be regarded as a draw-down electrode and is used when it is desired to use up most of the mixture in the tank 10 preparatory to cleaning or sterilizing. When this electrode, by reason of its longer length, is immersed in the liquid in the tank 10 and is in circuit the grounding of this electrode continues until most of the contents of tank 10 have been withdrawn. Then, when the longer electrode B is no longer immersed it will function in the same manner above described in conjunction with electrode A but causes a cycling of the apparatus to occur only when level in the storage tank 10 falls below its lower end.

The electrode C in the storage tank is a very short electrode that is constantly connected through the capacitor 19 to grid 2t). This electrode is used to prevent an overflowing of tank 10 in the event there is a malfunctioning of the tubes 35 and/or 36.

50 and 51 are merely push buttons used for manual control to manually perform the functions of contactors 27 and 28 as energized by relay 26 whenever desired. 52 and 53 are pilot lights which become energized Whenever the circuits through the motor-driven pump 14 and the solenoid valve 17 are energized.

It will be noted that relays 24 and 32 are shunted by capacitors. These capacitors are employed for the purpose of preventing chattering or buzzing of these relays when energized.

It will be appreciated from the above-described construction that when electrode A is connected in the circuit that when the liquid level falls below its lower end opening the ground connection with this electrode, that the gas-filled triode containing the anode 21 and cathode 22 allows relay 24 to be energized. This, in turn, energizes and closes relay 26 energizing the two resistance capacity networks and starts the operation of the motor-driven pump 14 and opens the solenoid valve 17. After a predetermined length of time relay 32 is energized opening the circuit through the motor-driven pump 14 and thus discontinuing further supply of syrup from the syrup reservoir 13.

After another predetermined length of time relay 40 is energized causing the solenoid valve 17 to close and shutting off the supply of water. This also results in a resetting of the entire apparatus for a subsequent cycle of operation. If the amount of water and syrup added has raised the level in receptacle 10 until the lower end of electrode A is again immersed, then the apparatus remains shut otf until the lower end of electrode A is uncovered. On the other hand, if the initial supply of syrup and water to the receptacle 10 has not covered the lower end of electrode A so as to ground it, the apparatus merely re-cycles until such a condition exists.

It will be appreciated that no high electric potential is impressed upon any of the electrodes A, B, or C, and that consequently the apparatus is not triggered or excited by the closing of any high potential circuit. Furthermore, as the solenoid valve 17 and the motor driven pump 14 require electric current to open the valve and drive the pump respectively which valve closes and the pump discontinues operation when electric current is no longer supplied, the construction will fail safe in the event of power failure or tube malfunction. Power failure or tube malfunction merely results in a discontinuance of further supply of water or syrup.

While the apparatus has been described as having been designed for the mixing of rootbeer syrup with water and the maintenance of an adequate supply of the mixture of these two liquids in the receptacle 10, it will be appreciated that the invention is not restricted thereto but that it can be used with any other pair of liquids that are to be mixed together. In fact, the number of liquids admitted to receptacle 10 can be increased beyond two by the mere addition of adding conduits leading to the receptacle, solenoid valves, or motor-driven pumps therein and appropriate resistance capacity networks timing their periods of operation after relay 24 has been energized and has caused the energizing of relay 26.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. An apparatus of the class described comprising a receptacle, means for withdrawing liquid from the receptacle, means for supplying a plurality of liquids to the receptacle, control means for opening and closing the supply of each liquid to the receptacle, timing means for each control means causing each control means to operate for a predetermined length of time only, and means responsive to the descent of liquid level in the receptacle for energizing the timing means to cause their respective control means to cause their respective liquids to be supplied to the receptacle in predetermined quantities.

2. An apparatus of the class described comprising a receptacle, means for withdrawing liquid therefrom, means for supplying a plurality of liquids to the receptacle, control means opening and closing the supply of each liquid to the receptacle, timing means for each control means causing each control means to operate for a predetermined length of time only, and means responsive to the descent of liquid in the receptacle for energizing the timing means to cause their respective control means to supply their respective liquids to the receptacle in predetermined quantities and then to discontinue further supply.

3. An apparatus of the class described comprising a receptacle, means for supplying a plurality of liquids thereto and withdrawing them therefrom, a timed control means for each liquid controlling the length of time that each liquid is supplied to the receptacle, and means responsive to a descent of liquid level in the receptacle for causing the timed control means for each liquid to supply its liquid to the receptacle for a predetermined length of time.

4. An apparatus of the class described comprising a receptacle, means for supplying a plurality of liquids thereto and withdrawing them therefrom, a timed control means for each liquid controlling the length of time that each liquid is supplied to the receptacle, means responsive to a descent of liquid level in the receptacle for causing the timed control means for each liquid to supply its liquid to the receptacle for a predetermined length of time, and then to discontinue the further supply of each liquid and to re-set the time control means to respond to a subsequent descent of liquid level in the receptacle.

5. An apparatus of the class described comprising means for supplying a plurality of liquids to the receptacle and withdrawing them therefrom, electrically operable control means for regulating the flow of each liquid to the receptacle, an electric timing circuit connected to each control means for timing the period that each control means enables its fluid to be supplied to the receptacle, and means responsive to a descent of liquid level in the receptacle below a predetermined degree for energizing the timing circuits.

6. An apparatus of the class described comprising means for supplying a plurality of liquids to the receptacle and withdrawing them therefrom, electrically operable control means for regulating the flow of each liquid to the receptacle, an electric timing circuit connected to each control means for timing the period that each control means enables its fluid to be supplied to the receptacle, an electrode suspended in the receptacle adapted to be connected to ground when immersed in liquid therein and to be disconnected from ground when the liquid level in the receptacle falls below the lower end of the electrode, a gas-filled triode having a grid electrically connected through a capacitor to the electrode, means for applying an electric potential to the cathode and anode of the triode, and means operable by the flow of current between the anode and cathode occasioned by the disconnecting of the electrode from ground for energizing said timing circuits.

7. An apparatus of the class described comprising a grounded receptacle, means for withdrawing liquid therefrom, an electrode suspended therein, means for supplying the receptacle with a plurality of liquids which when the liquid level rises to immerse the bottom of the electrode will ground the electrode and when the liquid level falls will disconnect the electrode from ground, a gasfilled triode having a grid electrically connected to the electrode through a capacitor, means for applying an electric potential to the cathode and anode of the triode, and means operable by the flow of current between the anode and cathode for causing a predetermined quantity of each liquid to be supplied to the receptacle.

8. An apparatus of the class described comprising a grounded receptacle, means for withdrawing liquid therefrom, an electrode suspended therein, means for supplying the receptacle with a plurality of liquids which when the liquid level rises to immerse the bottom of the electrode will ground the electrode and when the liquid level falls will disconnect the electrode from ground, a gasfilled triode having a grid electrically connected to the electrode through a capacitor, means for applying an electric potential to the cathode and anode of the triode, an electric timing circuit controlling the amount of each liquid supplied to the receptacle, and means operable by the flow of current between the anode and cathode of the gas-filled triode for energizing the electric timing circuits and thus causing a predetermined quality of each liquid to be supplied to the receptacle.

9. An apparatus of the class described comprising a grounded receptacle, means for withdrawing liquid therefrom, an electrode suspended therein, means for supplying the receptacle with a plurality of liquids which when the liquid level rises to immerse the bottom of the electrode will ground the electrode and when the liquid level falls will disconnect the electrode from ground, a gas-filled triode having a grid electrically connected to the electrode through a capacitor, means for applying an electric potential to the cathode and anode of the triode, an electric timing circuit controlling the amount of each liquid supplied to the receptacle, and means operable by the flow of current between the anode and cathode of the gas-filled triode for energizing the electric timing circuits and thus causing a predetermined quantity of each liquid to be supplied to the receptacle, said electric timing circuits being arranged in parallel and having resistances adapted to be simultaneously adjusted to prolong the timing of one circuit and shorten the timing of the other circuit, and vice versa.

10. An apparatus of the class described comprising a receptacle having an inlet and an outlet and in which liquid level may rise and fall as a result of liquid being supplied to and being Withdrawn from the receptacle, an electrode in the receptacle adapted to be immersed in the liquid and grounded when the liquid level is high, and uncovered and disconnected from ground when the liquid level is low, means for supplying the receptacle with liquid through its inlet, control means regulating the supply of liquid to the receptacle, a gas-filled triode having a grid connected through a capacitor to the electrode, means for applying electric potential to the cathode and anode of the gas-filled triode, and timing means operable by the flow of current between the anode and cathode while the electrode is not grounded controlling the operation of the control means to cause liquid to be supplied to the receptacle until completion of the timing cycles and the electrode is immersed in liquid and grounded and then discontinue further supply of liquid to the receptacle.

11. An apparatus of the class described comprising a receptacle having an outlet and means for supplying two liquids to the receptacle whereby liquid level in the receptacle may rise and fall as a result of liquid being supplied to and being withdrawn from the receptacle, an electrode in the receptacle adapted to be immersed in the liquid therein and grounded thereby when the liquid level is high and uncovered and disconnected from ground when the liquid level is low, means for supplying the receptacle with both liquids, control means regulating the supply of each liquid to the receptacle, a gas-filled triode having a grid connected through a capacitor to the electrode, means for applying electric potential to the cathode and anode of the gas-filled triode, a timing circuit for each control means operable when energized to cause the References Cited in the file of this patent UNITED STATES PATENTS Wolfner Sept. 5, 1944 Comb July 26, 1949 Wolfner Oct. 4, 1949 Pellerin ct al. Feb. 24, 1959 Reynolds Nov. 22, 1960 UNITED S ATES PATENT OFFICE CERTIFICATE OF CORRECTION Ratent No. 3,142,309 V July 28, 1964 Lee D. Minkler It is hereby certified that error appears in the above numbered pat-f ,ent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line 20, for "quality" read quantity Signed and sealed this 1st day of December 19640 (SEAL) Attest:

ERNEST W. SWIDER V EDWARD J. BRENNER rz mesting Officer 1 f Commissioner of Patents 

1. AN APPARATUS OF THE CLASS DESCRIBED COMPRISING A RECEPTACLE, MEANS FOR WITHDRAWING LIQUID FROM THE RECEPTACLE, MEANS FOR SUPPLYING A PLURALITY OF LIQUIDS TO THE RECEPTACLE, CONTROL MEANS FOR OPENING AND CLOSING THE SUPPLY OF EACH LIQUID TO THE RECEPTACLE, TIMING MEANS FOR EACH CONTROL MEANS CAUSING EACH CONTROL MEANS TO OPERATE FOR A PREDETERMINED LENGTH OF TIME ONLY, AND MEANS RESPONSIVE TO THE DESCENT OF LIQUID LEVEL IN THE RECEPTACLE FOR ENERGIZING THE TIMING MEANS TO CAUSE THEIR RESPECTIVE CONTROL MEANS TO CAUSE THEIR RESPECTIVE LIQUIDS TO BE SUPPLIED TO THE RECEPTACLE IN PREDETERMINED QUANTITIES. 